Solid state semiconductor light emitters are important devices in such diverse applications such as optoelectronic communication systems and high-speed printing systems. It is well-known in the proven art of silicon to provide suspension and actuation schemes, for example, comb drives using bending springs or parallel plate actuation using torsion springs. For optical beam steering applications, these silicon steering elements are typically combined with a light source in a separate package, or even with a light source xe2x80x98gluedxe2x80x99 or bonded onto the silicon steering chip. To make an integrated device, it is necessary to develop MEMS fabrication technology for GaAs-based materials, such techniques including deep etching techniques to make high aspect ratio structures. It is highly desirable to combine the optical characteristics of GaAs materials with the structural and electrical characteristics of silicon.
U.S. Pat. Nos. 5,536,988, 5,640,133, 5,629,790 and 5,025,346, xe2x80x9cFabrication of Submicron High-Aspect-Ratio GaAs Actuatorsxe2x80x9d Zhang et al., Journal of Microelectromechanical.Systems Vol. 2, No.2, p. 66-73, June 1993, xe2x80x9cLaterally Driven Polysilicon Resonant Microstructurexe2x80x9d Tang et al., IEEE Micro Electro Mechanical Systems pp. 53-59, February 1989 (reprint), and xe2x80x9cElectrostatic-comb Drive of Lateral Polysilicon Resonatorsxe2x80x9d Tang et al., Transducers ""89, Proceedings of the 5th International Conference on Solid-State Sensors and Actuators and Eurosensors III, Vol. 2, pp. 328-331, June 1990 (reprint) show the state of the art of micro-electromechanical systems (MEMS) actuators and methods of fabricating these devices. U.S. Pat. Nos. 5,747,366 and 5,719,891, H. J. Yeh, and J. S. Smith, xe2x80x9cIntegration of GaAs VCSEL on Si by substrate removalxe2x80x9d, Appl. Phys. Lett. Vol 64, pp. 1466-1468 (1994) and Y. H. Lo, et al. xe2x80x9cSemiconductor lasers on Si substrates using the technology of bonding by atomic rearrangementxe2x80x9d Appl. Phys. Lett. Vol. 62, pp. 1038-1040 (1993) show the state of the art of semiconductor light emitting assemblies.
U.S. patent application Ser. No. 08/761,681, entitled xe2x80x9cRaster Output Scanner with Pivotal Mirror for Process Direction Light Spot Position Controlxe2x80x9d filed on Dec. 6, 1996 and assigned to the same assignee as the present invention teaches a MEMS torsional control device.
U.S. patent application Ser. No. 08/940,867, entitled xe2x80x9cHighly compact Vertical Cavity Surface Emitting Lasersxe2x80x9d filed on Sep. 30, 1997 and assigned to the same assignee as the present invention teaches the formation of highly compact and well-defined VCSELs.
U.S. patent application Ser. No. 09/173,329, entitled xe2x80x9cMonolithic Scanning Light Emitting Devicesxe2x80x9d filed on Oct. 15, 1998 and assigned to the same assignee as the present invention teaches a micro-machined movable light emitting assembly formed on or from a III-V substrate, preferably a GaAs substrate. The movable light emitting assemblies are actuated using force generators to generate various degrees of movement depending upon the type of stage suspension and actuation mechanism used.
All of the above references are hereby incorporated by reference.
The present invention is drawn to integrating GaAs-based optical devices with Si-based MEMS structures. The proposed devices utilize superior optical properties of III-V compounds and superior mechanical properties of Si, as well as matured fabrication technologies of Si-MEMS. The emitter can be a light emitting diode (LED), a vertical cavity surface emitting laser (VCSEL) or an edge emitting laser. Electro or magnetic based actuation from Si-based actuator provides linear or angular scanning.